This invention relates generally to a printer of the type used for an electronic calculator, and the like, and more particularly to a printer using an electromagnet and having small size and low electrical energy consumption. In such applications as electronic calculators, an electromagnet, that is, a solenoid device has become an indispensable element for achieving reduced size and low energy input. However, the electromagnet is a principal part which consumes power in a printer and electromagnets suffer from many defficiencies. For example, efficiency is low and energy consumption is large in terms of the work accomplished. Peak current is high, which affects the size and life of the battery power supply which is conventionally used in portable calculators with printers. Also, the time required to actuate the electromagnet and attract a moveable element varies as the applied voltage varies in magnitude.
The problems of efficiency and peak current are resolved by making the electromagnet large. The problems of peak current and operation time are resolved by using a nickel-cadmium cell having a small internal resistance and a stable discharge characteristic. However, when using these solutions it is not possible to miniaturize the printer sufficiently to obtain a pocket-sized calculator with printer. Also, it is not possible to sufficiently lower power consumption of the printer so that it may be driven by an inexpensive consumable manganese cell (Mn). The manganese cell has an internal resistance which is larger than the nickel-cadmium cell and the discharge characteristic is less refined and uniform.
What is needed is a printer using an electromagnet which can operate on less expensive manganese cells and have small sized, efficient and uniform operation.